title: Peroxisomes and photomorphogenesis.
abstract: In higher plants, light-grown seedlings exhibit photomorphogenesis, a developmental program controlled by a complex web of interactions between photoreceptors, central repressors, and downstream effectors that leads to changes in gene expression and physiological changes. Light induces peroxisomal proliferation through a phytochrome A-mediated pathway, in which the transcription factor HYH activates the peroxisomal proliferation factor gene PEX11b. Microarray analysis revealed that light activates the expression of a number of peroxisomal genes, especially those involved in photorespiration, a process intimately associated with photosynthesis. In contrast, light represses the expression of genes involved in β-oxidation and the glyoxylate cycle, peroxisomal pathways essential for seedling establishment before photosynthesis begins. Furthermore, the peroxisome is a source of signaling molecules, notably nitric oxide, which promotes photomorphogenesis. Lastly, a gain-of-function mutant of the peroxisomal membrane-tethered RING-type E3 ubiquitin ligase PEX2 partially suppresses the phenotype of the photomorphogenic mutant det1. Possible mechanisms underlying this phenomenon are discussed.
authors.affiliation: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
authors.forename: Navneet
authors.initials: N
authors.lastname: Kaur
authors.forename: Jiying
authors.initials: J
authors.lastname: Li
authors.forename: Jianping
authors.initials: J
authors.lastname: Hu
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D008027:Light; D009569:Nitric Oxide / Q000378:metabolism; D020675:Peroxisomes / Q000378:metabolism / Q000528:radiation effects*; D063245:Plant Development / Q000528:radiation effects*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D015398:Signal Transduction / Q000528:radiation effects*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D009569:Nitric Oxide; D044767:Ubiquitin-Protein Ligases